Photographic bag

ABSTRACT

This disclosure relates to a bag constructed particularly for the packaging of products which are subject to further chemical reaction, i.e., chemical changes produced in substances by light being absorbed directly, by reflection, or by transmission, whether infrared or ultraviolet, as well as from the visible rays of the spectrum, the bag being formed as a seamless homogeneous one-piece tube flattened upon itself to define a pair of oppositely disposed flattened edge portions, the tubing constructed from synthetic generally opaque plastic material, the flattened material being folded upon itself at least once to bring the flattened edge portions into contiguous relationship and form at least a two-ply tubular member, means securing the edge portions to each other to define a tubular member having axially opposite end portions, and means closing at least one of said end portions.

United States Patent [151 3,647,134 Carnevalino 1 Mar. 7, 1972 [54]PHOTOGRAPHIC BAG [72] Inventor: Ernest Carnevalino, King of Prussia, Pa.Primary Examiner-Joseph Leela Assistant Examiner-Stephen MarcusAttorney-Diller, Brown, Ramik & Holt [57] ABSTRACT This disclosurerelates to a bag constructed particularly for the packaging of productswhich are subject to further chemical reaction, i.e., chemical changesproduced in substances by light being absorbed directly, by reflection,or by transmission, whether infrared or ultraviolet, as well as from thevisible rays of the spectrum, the bag being formed as a seamlesshomogeneous one-piece tube flattened upon itself to define a pair ofoppositely disposed flattened edge portions, the tubing constructed fromsynthetic generally opaque plastic material, the flattened materialbeing folded upon itself at least once to bring the flattened edgeportions into contiguous relationship and form at least a two-plytubular member, means securing the edge portions to each other to definea tubular member having axially opposite end portions, and means closingat least one of said end portions.

10 Claims, 5 Drawing Figures PAIENTEDMAR 11 12 INVENTOR ERNESTCQRNEVAUND ATTORNEYS PHOTOGRAPHIC BAG The present invention is directedto a bag or any other type container in which is adapted to be packagedproducts which are normally adversely affected by a photochemicalreaction, more specifically among which are such products asphotographic film or plates which after exposure must be maintained in alight-free atmosphere until developed. Though the present invention isdirected particularly to preventing direct light from being absorbed byexposed photographic film or plates, the bag of the present invention isuseful for packaging any product which is affected, either good or bad,by light rays, be they visible, infrared, ultraviolet, etc., and whetherthe light is reflected, transmitted or direct. As an example, exposedphotographic film or plates are packaged in so-called lightproof" bagsor similar containers because once having been exposed furtherabsorption of light by the silver salts of the film emulsion results inthe transfer of the silver salts into metallic silver, which whendeveloped, produce dark or overexposed area thus ruining the desiredexposure. This is true of both black-and-white and color film with theexception that in the latter there are a plurality of silversalt-emulsion layers with each layer containing a coupler to produce adesired colored dye. However, in each case, extraneous undesirable lightwill virtually ruin any exposure and though perhaps of major concern toamateur and professional photographers in general, more importanceshould be attached to such arts as photocomposition, photoengraving,photogrammetry, photographic copying, photomicrography, etc., whereinthe destruction of a particular exposure due to light leakage afterexposure and prior to development due to packaging defects would presenta vastly more important consideration than the loss of merely a goodsnap shot."

At present, the major problem of packaging exposed photographic films orplates is simply that of precluding the introduction of light rays, bethey visible, ultraviolet, or infrared into the interior of commerciallyavailable packages. Most important is what is known in the industry aspinholes which are simply voids which transmit light into the interiorof packages designed to house exposed photographic articles. Onesolution, though relatively expensive, is that of extruding a coating ofcarbon black pigmented synthetic plastic material, such as polyethylene,on dark (preferably black) paper, and forming the paper into a tubewhich eventually forms the liner of a duplex bag.

Another attempted solution is that of forming a laminate of at leastthree plies which eventually is formed into a bag in which an outer plyis formed of paperstock material, an inner ply of opaque pigmentedsynthetic plastic material, and an inner liner of metallic foil, or viceversa. From a commercial standpoint both of these so-called solutionsare costly since the first involves achieving as perfect as possible adispersion between the opaque pigmentation and the plastic material, theuniform application of the latter upon the dark paper, and thereafterthe unification of this two-part construction to an outer overwrap. Asto the latter, this adds the additional difficulty in cost involved inlaminating a foil liner and/or overwrap thereto.

Another common duplex bag for this purpose employs paperstock material,such as kraft paper and a laminated opaque pigmented polyethylene liner.In order to gain maximum opacity the polyethylene liner is generallypigmented with carbon black or any similar type opaque substance.However, even when the carbon black pigmentation rate is relatively highand the gage of the polyethylene film is two or three mils, a completelyopaque bag does not always result because of occasional pinholes" in thefilm due to gel particles, incomplete pigment dispersion, and the like.As was heretofore noted, such areas of light transmission can and willresult in the damage or total loss of exposed film, be it photographicfilm, photographic plates, or even the fogging of X-ray film.

In order to practically, though not necessarily, eliminate thepossibility of light penetrating into the interior of this structure, itmight be theoretically feasible to employ two pigmented polyethyleneliners, each of which would be somewhat thinner than the single linerheretofore noted. This might be effective since the possibility of theoccasional pinholes in the two films actually coinciding or aligningwould be virtually nil. However, the use of two polyethylene or anyother type liners is not practical for a variety of reasons. First, thesimultaneous machining of two separate extremely lightweight andextensible or stretchable liners on commercial bag machines is virtuallyif not totally impossible and if possible would undoubtedly result inextremely low operating speeds and high waste. Furthermore, there are noknown commercially available adhesives of the emulsion-type required'onbag machines which will provide adequately strong bonds between the twopolyethylene plies either in the bag body or the bag bottom. Finally,even should such adequate emulsion-type adhesives be developed for thispurpose the use between two relatively moisture impermeable plies offilm, such as polyethylene, would necessarily result in the need to age"the bags several weeks before use so as to provide an opportunity forair to dry out and setup the adhesive.

In keeping with the foregoing invention, each and every of the foregoingnoted disadvantages of known lightproof packages have been eliminated bythe construction of a bag in keeping with the present invention which isformed as a seamless homogeneous one-piece preferably extruded tube ofsynthetic plastic material containing a random dispersion of impregnatedopaque material, the tube being flattened upon itself, and thereafterthe flattened tube being folded upon itself at least once to bringflattened edge portions into contiguous relationship. After having beenlongitudinally seamed along the flattened edge portions and transverselyclosed any light-transmitting voids produced by the dispersion in eitherof the two plies will invariably not fall into alignment due to theflattening of the tube upon itself.

By this structure alone, it should be first noted that the bag can beconstructed from but a single tubular member, and if desired the samemay be provided with an outer overwrap. However, in the latter case, itis unnecessary to extrude the plastic-opaque dispersion upon a darkpaper background to form a liner and if desired unite the same with anoutenvrap or unite three plies as in the case of commercially availablepaper-pigmented plastic-foil packages. Moreover, the difficulty ofextruding two thin extensible webs, adhesively uniting the same,longitudinally seaming the same, and then using the same individually orwith an overwrap is also avoided. Finally, in the latter case theproblem of adhering impermeable plastic web material to each other toform commercial bags of the type heretofore described is avoided sinceit is absolutely unnecessary and in fact undesirable to adhere opposingsurfaces of the flattened tube to each other. Furthermore, whether usedin the absence of an overwrap or with an overwrap each disadvantage ofcommercially known lightproof bags is eliminated by the bag and/or linerof the present invention.

With the above and other objects in view that will hereinafter appear,the nature of the invention willbe more clearly understood by referenceto the following detailed description, the appended claims and theseveral views illustrated in the accompanying drawing.

IN THE DRAWING:

FIG. 1 is a perspective view of a novel bag constructed in accordancewith the invention with portions thereof broken away for clarity, andillustrates a seamless homogeneous onepiece tube flattened upon itselfwith flattened longitudinal edge portions being heat-sealed to eachother to define a lightproof bag which is usable per se or inconjunction with an outerwrapper to form a duplex bag.

FIG. 2 is a diagrammatic sectional view taken through the flattened bagor liner of H6. 1 prior to the same being folded upon itself in themanner indicated by the unnumbered headed arrows.

FIG. 3 is a view similar to FIG. 2 illustrating flattened longitudinaledge portions of the liner and/or bag in contiguous relationship, andindicating the manner in which opposing plies are sealed to each other.

FIG. 4 is an enlarged sectional view taken generally along line 4-4 ofFIG. 1, and illustrates the flattened, folded upon itself andlongitudinally seamed tubular member forming a liner in association withthe outerwrapper.

FIG. 5 is an enlarged fragmentary sectional view taken generally alongthe line 5-5 of FIG. 1 prior to the completion of the bag, andillustrates the manner in which the bottom end portion is twice foldedupon itself to complete the fabrication of the duplex bag.

Before describing a preferred embodiment of the present invention, it ispointed out hereinat that the present invention is directed primarily toa bag formed as a seamless homogeneous one-piece tube constructed fromsynthetic generally opaque plastic material flattened upon itself todefine a pair of oppositely disposed flattened edge portions which arefolded into contiguous relationship and sealed to each other to form atubular member which when closed forms a lightproof structure whicheliminates the disadvantages heretofore noted with respect toconventional packages.

Though the bag is preferably of a duplex structure i.e., is fonned withthe opaque flattened and folded tube constituting a liner associatedwith an outer overwrap, it is to be understood that the liner" per semay be a bag per se and need not be used in association with the outeroverwrap. Moreover, though the tube is disclosed as being flattened uponitself and folded but once to bring longitudinal folded edge portionsinto lap relationship with each other, it is to be understood that morethan but a single folding may be employed to form more than but atwo-ply structure.

Referring particularly to FIG. 1 of the drawing, a novel bag constructedin accordance with this invention is generally designated by thereference numeral and as a preferred embodiment of the invention the bag10 is a duplex bag which includes an inner bag or liner 1 1 and an outerbag or overwrap 12.

The overwrap 12 is of a completely conventional construction and isconstructed from paperstock material, such as kraft paper, or any otherflexible foldable material which from a web is formed into a tube havinga front wall or panel 13, a rear wall or panel 14, opposite gussettedsidewalls or panels 15, 16, and a bottom portion 17 folded upon itselftwice with adhesive A (FIG. 5) uniting the lowermost portions(unnumbered) of the walls 13, 14 to each other in a conventional manner.Longitudinal edges 18, 20 are, of course, adhesively secured to eachother by adhesive, which is indicated by the stippling in FIG. 1, or byany other conventional means.

The liner or bag 11 of the duplex bag 10 is designed particularly forthe packaging of products which are subject to photochemical reaction,as was heretofore noted, and comprises a seamless homogeneous one-piecetube flattened upon itself (FIG. 2) to define a pair of oppositelydisposed flattened edge portions 21, 22. The tube or bag 11 isconstructed from synthetic generally opaque plastic material, such aspolymeric or copolymeric plastic material, most preferably of which ispolyethylene. The flattened tube, which for purposes of discussion willbe more specifically designated by the reference numeral 23 (FIG. 2)includes in addition to the folded longitudinal edge portions 21, 22,two walls or plies 24, 25. The tube 23 is of a predetermined length andthus includes unnumbered upper and lower end portions, the latter ofwhich is closed upon the folding of the duplex bag 10 and the securementof the walls 13, 14 to each other by the adhesive A in the mannerheretofore noted.

In addition to being constructed from plastic material, the tube 23 isextruded after the material thereof has been first intermixed with agenerally opaque material nontransmissive to light, such as carbonblack. The opaque material is admixed with the plastic material(polyethylene or the like) and is formed into an impregnated dispersionwhich under ultimate conditions would prevent the transmission of light.However,

even if the opaque dispersion (carbon black or an equivalent material)is relatively high and the thickness of the film is similarly high (23mils) a completely opaque bag will not always result because ofoccasional pinholes" (light-transmitting voids) in the film due to gelparticles, incomplete pigment dispersion, and the like. To prevent suchlight transmission and avoid the disadvantages in known packagesheretofore noted, the tube 23 is first flattened upon itself (FIG. 2)and is then folded upon itself at least once to .form a folded two-plytubular member 30 (FIG. 3). The flattened edge portions 21, 22 are inoverlapped relation but, as claimed, the term contiguous is intended tomean not only the overlapped relation illustrated in FIGS. 1, 3 and 4,but also end-toend butt relationship or a space relationship with anytype seam therebetween such as a strip of tape extending along thelongitudinal length of the edge portions 21, 22 so long as the tape isof a lightproof construction. Moreover, a fin" type seal is alsointended by the term contiguous as is any construction in which the edgeportions 21, 22 are joined to each other in any manner, either directlyor by an intervening structure.

Upon folding the flattened tube 23 upon itself to form the tubularmember 31) the flattened tube 23 is likewise provided with flattenedinner folded edge portions 31, 32 of a two-ply construction, as opposedto the four-ply construction of the edge portions 21, 22. Furthermore,instead of being of a single ply asis the flattened tube 23 defined bythe walls 24, 25, the tubular member 30 is of a two-ply constructiondefined by the now folded upon themselves walls 24, 25 which forpurposes of description are indicated more exactingly by the referencenumerals 34, 35 indicating the respective outer and inner plies of thetubular member 30. As is best illustrated in FIG. 4, the contiguous edgeportions 21, 22 of the tubular member 30 are secured to each other bylongitudinal seam 36 which is preferably a heat-seal between the portion(unnumbered) of the plies 34, 35 in opposed relationship to each otherat the edge portions 21, 22. Though the heat seal 36 is a preferable wayof adhering the edge portions 21, 22 to each other, it is to beunderstood that other conventional means may be employed for thispurpose.

The tubular member 30 includes, of course, upper and lower end portions(unnumbered) which are coincident with those of the outerwrapper 12, andthe lower end portions is, of course, closed upon the overfolding endsecurement of the wall 13, 14 to each other by the adhesive A. However,it is to be particularly noted that apart from the adhesive A and thesecuring means 36 no further securement is provided between the outerply 34 and the inner surface (unnumbered) of the outerwrapper 12 orbetween the outer ply 34 of the tubular member 311 and the inner ply 35thereof. Adhesive may, of course, be provided between the outer surfaceof the outer ply 34 of the tubular member 30 and the inner surface ofthe outerwrapper 12. However, most importantly, is the fact that nomeans whatever is provided for securing the inner surface of the outerply 34 of the tubular member 30 to the outer surface of the inner ply35, as is clearly indicated in FIG. 3. This is important because, as washeretofore noted, emulsion-type adhesives are presently unavailable foradequately securing moisture-impermeable material, such as a materialfrom which the tubular member 30 is constructed, to itself. Moreover, aswas heretofore noted even if such type adhesives were developed, andthey were applied between the plies 34, 35 it would be necessary to ageor store the eventually formed duplex bags and to permit air to set orcure such adhesives prior to shipment and/or use. Thus, by forming theflattened tube 11 as a seamless homogeneous blow-mold member, it isunnecessary to adhere the plies of the eventual folded tubular member 30to each other thus avoiding the added cost of storage space which wouldbe required for the purpose of aging or curing the adhesive and,moreover, production is increased since the only two seals which formthe duplex bag 10 are the seals 36, which is a heat-seal requiringlittle or negligible aging and the seal formed by the adhesive A whichbecause it is between a paper-paper interface is aged or curedsufficiently after leaving the bag-forming machine to be stacked,packaged and shipped in the absence of interim storage. This is becausethe paperstock material of the overwrap 12 is porous and air and/or heatrapidly sets the adhesive, and thus there is no delay time prior toshipping as might be necessitated if an adhesive were applied betweenthe impermeable plies 34, 35 of the tubular member 30.

It is pointed out that the construction of the duplex bag is formed in acontinuous manner by first extruding a tube of thermoplastic material,flattening the extruded tube to fonn the tube 11, folding the tube 11 toform the tubular member 30, seaming the edge portions 21, 22 of thelatter as the same is being continuously advanced, and at the same timeoverwrapping the overwrap l2 thereupon and forming the longitudinal seamafter which transverse severing of individual lengths and the closure ofone end to form the bag 10 is completed in a well known fashion.Furthermore, though the duplex bag 10 is disclosed as being providedwith gussetted sides 15, 16, these may be eliminated and/or altered asmay be necessary, as may be the particular construction of the bottomclosure of the bag by the adhesion of the wall 13, 14.

It is further emphasized that though the folding of the flattened tubell upon itself has been indicated as being a direct fold of the edgeportions 21, 22 upon themselves, as shown in FIG. 3, additional foldingprior to securement may be provided. For example, instead of the foldingindicated by the unnumbered headed arrows in FIG. 2, the edge portions21, 22 could be brought into overlying relationship but directed in thesame direction to form another longitudinal fold remote therefrom andthe latter longitudinal fold could then be brought into overlappedrelationship to the edges 21, 22 after which longitudinal seaming couldbe achieved. This would achieve added plies equivalent, of course, tofolding the tubular member 30 to bring the edges 31, 32 into continguousrelationship after which the same could be longitudinally seamed. Thisproduces additional assurance against light transmission but does so atadded cost, but reference thereto is believed necessary to highlight theintent of the following claims.

Irrespective of the particular configuration of the bag or liner 10, itis to be understood that the essence of the present invention is that offirst forming the tube 11 as a homogeneous nonlight transmissive memberwhich, though it may have pinholes, by simply flattening the same to theconfiguration shown in FIG. 2 alignment of any pinholes in the plies 24,is virtually, if not positively, precluded. Thus, imagining photographicfilm or plates being housed interiorly of the inner ply 35 of thetubular member with the edge portions 21, 22 seamed, exterior light mustnot only pass through pinholes of the exterior ply 34 but must also passthrough aligned pinholes of the interior ply 35 before the contents ofthe bag 10 could be damaged. Due to the virtual impossibility of suchalignment of pinholes the bag 10 is lightproof."

Iclaim:

1. A bag constructed particularly for the packaging of products whichare subject to photochemical reaction comprising a seamless homogeneousone-piece tube flattened upon itself to define a pair of oppositelydisposed flattened edge portions, said tube being constructed fromsynthetic v generally opaque plastic material, said flattened tube beingfolded upon itself at least once to bring said flattened edge portionsinto contiguous relationship and form at least a twoply tubular member,means securing said edge portion to each other to define a tubularmember having axially opposite end portions, and means closing at leastone of said end portions.

2. The bag as defined in claim 1 wherein the opaque nature of saidplastic material is defined by opaque material impregnating said plasticmaterial.

3. The bag as defined in claim 1 wherein the opaque nature of saidplastic material is defined by opaque material impregnating said plasticmaterial, and said opaque material is randomly disposed in said lasticmaterial whereby any lighttransmitting work produce by said dispersionin either of said at least two plies are prevented from transmittinglight to the bag interior by the other of said two plies due to theflattening of said tube upon itself.

4. The bag as definedin claim 1 wherein said tube is formed by extrudingan admixture of said plastic material containing a random dispersion ofopaque material.

5. The bag as defined in claim 1 wherein said two plies are free of eachother over substantially the entire interior extent of said tubularmember excluding said securing and closing means.

6. The bag as defined in claim 1 including an outer overwrap membersubstantially housing said tubular member.

7. The bag as defined in claim 1 wherein said securing means is a heatseal.

8. The bag as defined in claim 1 including an outer overwrap membersubstantially housing said tubular member, and means securing anoutermost ply of said tubular member to said overwrap member between theaxially opposite end portions of the latter.

9. The bag as defined in claim 1 including an outer overwrap membersubstantially housing said tubular member, means securing an outermostply of said tubular member to said overwrap member between the axiallyopposite end portions of the latter, said plastic material beingsubstantially moisture impermeable, said overwrap member being moisturepermeable, and said last-mentioned means being an air-setting adhesive.

10. The bag as defined in claim 1 wherein said flattened tube is devoidof adhesive means between innermost opposing surfaces thereof.

1. A bag constructed particularly for the packaging of products whichare subject to photochemical reaction comprising a seamless homogeneousone-piece tube flattened upon itself to define a pair of oppositelydisposed flattened edge portions, said tube being constructed fromsynthetic generally opaque plastic material, said flattened tube beingfolded upon itself at least once to bring said flattened edge portionsinto contiguous relationship and form at least a two-ply tubular member,means securing said edge portion to each other to define a tubularmember having axially opposite end portions, and means closing at leastone of said end portions.
 2. The bag as defined in claim 1 wherein theopaque nature of said plastic material is defined by opaque materialimpregnating said plastic material.
 3. The bag as defined in claim 1wherein the opaque nature of said plastic material is defined by opaquematerial impregnating said plastic material, and said opaque material israndomly disposed in said plastic material whereby anylight-transmitting work produced by said dispersion in either of said atleast two plies are prevented from transmitting light to the baginterior by the other of said two plies due to the flattening of saidtube upon itself.
 4. The bag as defined in claim 1 wherein said tube isformed by extruding an admixture of said plastic material containing arandom dispersion of opaque material.
 5. The bag as defined in claim 1wherein said two plies are free of each other over substantially theentire interior extent of said tubular member excluding said securingand closing means.
 6. The bag as defined in claim 1 including an outeroverwrap member substantially housing said tubular member.
 7. The bag asdefined in claim 1 wherein said securing means is a heat seal.
 8. Thebag as defined in claim 1 including an outer overwrap membersubstantially housing said tubular member, and means securing anoutermost ply of said tubular member to said overwrap member between theaxially opposite end portions of the latter.
 9. The bag as defined inclaim 1 including an outer overwrap member substantially housing saidtubular member, means securing an outermost ply of said tubular memberto said overwrap member between the axially opposite end portions of thelatter, said plastic material being substantially moisture impermeable,said overwrap member being moisture permeable, and said last-mentionedmeans being an air-setting adhesive.
 10. The bag as defined in claim 1wherein said flattened tube is devoid of adhesive means betweeninnermost opposing surfaces thereof.